Role of protein kinase C in basal and hydrogen peroxide-stimulated NF-kappa B activation in the murine macrophage J774A.1 cell line.
In macrophages, hydrogen peroxide appears to be a physiological activator of the transcription factor, nuclear factor kappa B (NF-kappa B); however, the molecular basis of H2O2-stimulated NF-kappa B activation is not well defined. The observations that NF-kappa B can be activated in cells by phorbol 12-myristate 13-acetate and in vitro by addition of protein kinase C (PKC) are suggestive of a role of PKC in NF-kappa B activation, which was investigated in the J774A.1 murine macrophage cell line. Basal NF-kappa B DNA-binding activity and nuclear localization were decreased by PKC inhibitors. Although PKC activity was modified by H2O2 with a similar time course as H2O2 activation of NF-kappa B, the H2O2-stimulated increase in NF-kappa B DNA binding and translocation to the nucleus was unaffected by PKC inhibitors. Furthermore, PKC down-regulation (through preincubation with phorbol esters) also affected only baseline NF-kappa B DNA binding but not H2O2-stimulated NF-kappa B activation. Buffering of changes in intracellular free calcium concentration also had no effect upon H2O2-stimulated NF-kappa B activation. Thus, classical PKC activity may modulate basal NF-kappa B activity but does not participate in H2O2-stimulated NF-kappa B activation.
Kaul
N
N
Department of Molecular Pharmacology & Toxicology, University of Southern California, Los Angeles 90033, USA.
Gopalakrishna
R
R
Gundimeda
U
U
Choi
J
J
Forman
H J
HJ
D000818:Animals; D001692:Biological Transport; D002118:Calcium / Q000378:metabolism; D002451:Cell Compartmentation; D002460:Cell Line; D002467:Cell Nucleus / Q000378:metabolism; D015536:Down-Regulation; D004533:Egtazic Acid / Q000031:analogs & derivatives / Q000494:pharmacology; D006861:Hydrogen Peroxide / Q000494:pharmacology; D008264:Macrophages / Q000187:drug effects / Q000378:metabolism*; D051379:Mice; D016328:NF-kappa B / Q000378:metabolism*; D018384:Oxidative Stress / Q000502:physiology*; D011485:Protein Binding; D011493:Protein Kinase C / Q000037:antagonists & inhibitors / Q000378:metabolism*
D016328:NF-kappa B; C070379:1,2-bis(2-aminophenoxy)ethane N,N,N',N'-tetraacetic acid acetoxymethyl ester; D004533:Egtazic Acid; D006861:Hydrogen Peroxide; D011493:Protein Kinase C; D002118:Calcium